Radio receiving apparatus



Nov. 10, 1931. A. o. STAHEL .RADIO RECEIVING APPARATUS Filed Jan. 23. 1929 jf i'alzw 0.

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Patented Nov. 10, 1931 UNITED STATES ADRIAN 0. STAHEL, OF ST. PAUL, MINNESOTA RADIO RECEIVING APPARATUS Application filed January 23, 19291 stein No. 334,460.

This invention relates to radio receiving apparatus, and has more particular reference to an accessory for apparatus of this kind embodying means operable at will to, connect the aerial terminal of a radio receiving set to the ground and simultaneously disconnect such terminal from the aerial and the ground terminal of the set from the ground, thereby improving reception by increasing selection and volume, securing reception from a greater distance, and eliminating static, interference and noise, under certain operating conditions.

A more specific object of the present in- 13 vention is to provide a device to improve reception of a radio receiving set under varying operating conditions, such device being operable at will to simultaneously disconnect the ground and aerial from the set, to simultaneously connect the ground to the ground terminal of the set and the aerial to the aerial terminal of such set, or to connect the ground to the aerial terminal of the set and simultaneously disconnect said aerial terminal from 115 the aerial and the ground terminal of the set from the ground.

\Vith the above objects in view, the invention consists of the novel combination, arrangement and form of parts hereinafter more fully described, shown in the accompanying drawings, and claimed.

In the drawings:

Figure 1 is a somewhat diagrammatic view showing an embodiment of the present invention in the form of a knife switch, operatively associated with a radio receiving apparatus.

Figure 2 is a front elevational view of the knife switch of Figure 1, with the movable member of the switch in a different operative position; and

Figure 3 is a side elevation of the knife switch as shown in Figure 1, two different positions of the movable switch member being indicated by dotted lines.

Referring more in detail to the drawings, the radio receiving apparatus is shown as including a conventional receiving set 5 having a. ground terminal 6 whichis usually constantly connected to a ground 7 ,and an aerial terminal 8 which is usually constantly co-nnectedtoan aerial 9.

I have found that, while under certain operating and atmospheric conditions satisfactory reception can be obtained with the usual connection of the ground terminal of the set with the ground and the aerial terminal thereof with the aerial, better reception may be obtained under other conditions if the ground is connected to the aerial terminal of the set whilesimultaneously disconnecting the ground terminal from the ground and the aerial terminal from the aerial. The present invention embodies the provision of means operable at will to effect as the last mentioned relation of elements.

While this means may take any oneof many forms, it is illustrated by way of example and preference as a special form of knife switch. As shown, this switch includes an insulating base 10 having a pair of contacts 11 and 12 at one end and at least one contact 13 at the other end, a movable switch member composed of a pair of rigidly connected contact blades let and 15 insulated 7 from each other and pivoted at 16 to the base 10 to swing to one position with the blade 14 engaged with the contact 11 and the blade 15 engaged with the contact 12 as shown in Figure 2, or to another position with the blade 15 engaged with the contact 13 as shown in Figure 1, and a jumper wire 17 or equivalent constant electrical connection between contacts 11 and 13.

In use, the ground terminal 60f the receiving set is connected by a conductor 18 with the pivoted end of the blade 14, the aerial terminal 8 is connected b a conductor 19 with the pivoted end of t e blade 15, the contact 11 is connected by a conductor 0 20 to the ground 7 and the contact 12 is connected by a conductor 21 to the aerial 9. By swinging the blades 14 and 15 into engagement with the contacts 11 and 12 asshown in Figure 2, the usual connection of the aerial 9 95 with the aerial terminal 8 and of the ground 7 with the ground terminal6 maybe effected. However, by swinging the blades out of engagement with the contacts 11 and 12 and the blade 15 into engagement with the con .100

tact 13 as shown in Figure 1, the ground 7 is connected with the aerial terminal 8, and the ground terminal 6 is disconnected from the ground, while the aerial terminal is simultaneously disconnected from the aerial. In the latter position, I have found that under certain conditions the volume anddistance of reception is increased, while static, interference and noise are eliminated. Under some conditions it is desirable to simul taneously disconnect the ground and aerial from the set, and this may be accomplished by disengaging the blades 14: and 15 from all of the contacts as indicated by the dotted line intermediate position of the movable switch member in Figure 3.

Numerous changes in the form and arrangement of parts are contemplated within the scope of the invention as claimed. It is further believed that the various connections may be readily traced without a more detailed discussion thereof.

\Vhat I claim as new is:

1. The combination with a radio receiving set having ground and aerial terminals, a ground, and an aerial, of means operable at will to connect the ground to said aerial terminal and simultaneously disconnect the ground terminal from the ground and the aerial terminal from the aerial.

2. The combination with a radio receiving set having ground and aerial terminals, a ground, and an aerial, of means operable at will to connect the ground to said aerial terminal and simultaneously disconnect the ground terminal from the ground and the aerial terminal from the aerial, said means being further operable at will to normally connect said aerial terminal to the aerial and simultaneously connect the ground terminal to the ground.

3. The combination with a radio receiving set having ground and aerial terminals, a

ground, and an aerial, of means operable at will to connect the ground to said aerial terminal and simultaneously disconnect the ground terminal from the ground and the aerial terminal from the aerial, said means being further operable at will to normally connect said aerial terminal to the aerial and simultaneously connect the ground terminal to the ground, or to simultaneously disconnect the aerial and ground from the set.

4. A radio accessory of the character described comprising a double-blade knife switch having a pair of contacts simultaneously engageable by the blades thereof and respectively adapted for connection with an aerial and a ground, a further contact engageable by one of said blades when the latter are disengaged from said pair of contacts, a constant electrical connection between said further contact and the contact of said pair adapted for connection with the ground, and means to facilitate connection of said blades respectively with the ground and aerial terminals of a radio receiving set.

5. A radio accessory of the character described embodying a switch comprising a pair of stationary contacts respectively adapted for connection with an aerial and a ground, a pair of movable contacts simultaneously engageable with said pair of stationary contacts, a further stationary contact engageable by one of said movable contacts when the latter are disengaged from said pair of stationary contacts, a constant electrical connection between said further contact and the contact of said pair adapted for connection with the ground, and means to facilitate connection of said movable contacts respectively with the ground and aerial terminals of a radio-receiving set.

In testimony whereof I afiix my signature.

ADRIAN O. STAHEL. 

